Dr. Julie, a.k.a. Scientific Chick, brings you insights into what's happening in the world of life sciences. Straight from the scientific source, relevant information you should know about, in plain language.

Saturday, December 15, 2012

On most days I bike to work. It’s my way of “walking the
walk” – I write enough about the benefits of exercise, it would be a little embarrassing
if I were a couch potato. Riding in involves climbing a big hill early(ish) in
the morning, but I usually just get into a low gear and think about stuff and I
barely notice it.

Not this morning.

This morning, there was a headwind. A cold headwind. It felt
like I was pedaling against a wall. I was trying to convince myself that I was
enjoying it – looking at the view, trying to feel the oxygen in my brain. But
at some point I let out a big sigh and thought “who am I kidding, this is
miserable!”.

Even so, I knew full well that tomorrow, I would be back on
the bike first thing in the morning. So I wondered – why do I continue to bike
in, even in the winter, in the rain, in the cold, up the hill – even though I
sometimes don’t derive any immediate pleasure or benefit? The answer, of
course, is that rationally, I know that no matter how miserable it is at the
moment, in the long run it’s good for me – it’s good for my health, my weight,
my ability to prevent and fight illness, and, as anyone who reads this blog
knows, my ability to ward off cognitive decline as I get older.

This process of holding off on immediate rewards (driving in
to work in a warm car with some Christmas music playing) to benefit from later
rewards (health) is called delayed gratification. It was most famously studied
using marshmallows: in a well-known study, young children were given the choice
between eating one marshmallow immediately, or waiting a few minutes and
receive two marshmallows (giving rise to some pretty hilarious antics). The
researchers followed-up on the children many years later, and found those who
were successful in displaying delayed gratification (and so resisted eating the
one marshmallow) were doing better on several outcomes such as academic success
and ability to handle stress.

In a more recent study, a team of researchers investigated
whether there is a link between the ability to delay gratification as a child
and weight in adulthood. They found that one’s performance on a delayed
gratification task (similar to the marshmallow experiment) was associated with
his or her body mass index (BMI) thirty years later. In short, the kids who
were able to wait the longest for a bigger reward had lower BMIs as adults.
Interestingly, another study found that children who already have a high BMI
score poorly on a delayed gratification task – a nice convergence of evidence
from different sources.

Avid Scientific Chick readers can no doubt point to an
important limitation of this study. Repeat after me: correlation does not imply
causation. The fact that kids who did well at delayed gratification later had
lower BMI’s does not mean that being good at delayed gratification causes one to have a lower BMI. There
are several potential confounders here, some of which were not controlled for,
such as the BMI of the participants as children. That said, the findings remain
interesting – it’s not completely out of the park to think that improving
self-regulation and self-control could have an impact on weight.

There is a little coda to my earlier story about biking
against a wall of wind.

About halfway up the hill, at the peak of my frustration,
almost as if on cue, a huge coyote emerged from the forest, and started
trotting along the bike path as I was biking. It was a big fluffy beast, and
for a second I was scared, but it was minding its own business, and eventually
started making its way across the street. Still excited from my encounter, I
turned my head, and there was another equally huge coyote sitting just next to
the bike path, in the forest, staring me down. I couldn't believe it. I've seen
coyotes before, but never this big, never this close, and never on my way to or
from work. They were beautiful creatures and my heart was warmed. Delighted
with this turn of events, and with the fact that this morning’s gratification
was instant and not delayed, I grinned like an idiot all the way to work.

About Me

Dr. Julie is an Assistant Professor of Neurology at the National Core for Neuroethics and the Djavad Mowafaghian Centre for Brain Health at the University of British Columbia. She holds a PhD in Neuroscience.